A nuclear power plant control system that controls a nuclear power plant is requested to regularly test each function to maintain high reliability. For example, a test of each function of the nuclear power plant control system that controls a nuclear power plant is conducted using test equipment during a periodical check when a nuclear reactor is shut down (for example, see Patent Literature 1).
Recently, by applying a digital control device, software within a control device included in a nuclear power plant control system may maintain reliability through self-examination without a conventional periodical test. For this reason, a portion using a manual test is a hard-wired device (switch, cable, and the like) of an external unit or an input/output unit.